Summary: Benralizumab (Fasenra®), an anti-IL-5 receptor a-chain monoclonal antibody, together with other anti-IL-5 antibodies (mepolizumab and reslizumab), represent a novel therapeutic option in severe asthma management. Interleukin 5 (IL-5) is a key cytokine involved in the maturation, recruitment and survival of eosinophils, thus playing an important role in the development of eosinophilic inflammation underlying allergic diseases and asthma. Benralizumab leads to significant depletion of eosinophils in airway mucosa, blood, sputum and clear inhibition of eosinophil differentiation and maturation in the bone marrow. In clinical studies benralizumab significantly reduces the rate of asthma exacerbations and has a clear oral glucocorticoid sparing effect. The frequency and type of reported adverse events do not differ between active treatment and placebo arms.